The invention relates to a control method for a balancing lifting gear and, in particular, for use with a lifting gear having a lifting motor which can be actuated by a controller and uses a control handle with a force sensor to lift and lower a load-supporting device. The invention also relates to a balancing lifting gear having a lifting motor which can be actuated by a controller and uses a control handle with a force sensor to lift and lower a load picking-up means, also referred to herein as a load-supporting device.
The German utility model DE 201 00 584 U1 discloses a so-called balancing lifting gear or a so-called cable balancer. A cable balancer includes a cable winch, a control handle and a load-supporting device and enables an operator to lift or lower a load, which is fastened to the load-supporting device, in a type of floating state in an almost weightless manner. A controller which is allocated to the cable winch balances the weight force of the load so that a manual force is applied by an operator to the load, the load-supporting device, or the control handle effects lifting or lowering of the load, depending upon the direction in which the manual force is effective. The controller can select the lifting or lowering speed in proportion to the applied force. In order to determine the manual force, a force sensor is disposed in the control handle at the transition from the upper end of the control handle to the cable. The weight of the load can also be measured by this force sensor and, by means of a change in weight force, it is possible to determine the manual force which serves a control variable for the controller and the lifting and lowering speed determined therefrom. The response behavior of the cable balancer can also be adjusted from gentle to aggressive in the controller.
In addition to the previously described “Balance” operating mode, a further operating mode of “Up/down control” is provided. For this purpose, the control handle is provided with an actuating ring which can be actuated in the upwards or downwards direction by the operator using his thumb to apply a force. The actuating ring is connected to a further force sensor, whose signals are supplied to the controller for lifting and lowering the load. When the actuating ring is used, a switch is made automatically from the “Balance” operating mode to the “Up/down control” operating mode.
It is generally known that such balancing lifting gears or cable balancers are used in different industrial processes, in which loads are moved and positioned in an exact manner by an operator. This relates, e.g., to manufacturing processes, in which one component is to be transported to another component and is to be attached thereto. The balancing lifting gears have been developed in order to reduce the amount of work for the operator in such a case.
Laid-open document US 2005/0267638 A1 discloses a control system for floor-free conveyors within the domain of assembly lines. The control system can be configured to adapt the floor-free conveyors in the form of cranes and balancing lifting gears, in particular their movement paths, to suit the individual assembly tasks. Semi-automatic movements can be provided or, e.g., the floor-free conveyor can return automatically to a starting position. In relation to the balancing lifting gears used, provision is made to adapt their response behavior to suit the users. For this purpose, maximum lifting and lowering speeds, maximum lifting and lowering accelerations, maximum and minimum lifting heights and the response sensitivity of the balancing lifting gear can be adjusted with respect to the balancing lifting gear. For this purpose, a corresponding display and various operating switches are provided in the region of a handle of the balancing lifting gear. In this control system, it is also possible to define specific regions, in which the floor-free conveyors cannot enter, in order to prevent collisions with parts of a building or machines, or the like.